Asus A55M-A Mobo
AMD Richland A-10 6800k CPU
2x Kingston hyper X beast 4GB ram
Gfx Radeon R9280x card
PSU Aurum 92 series PT 550M
NZXT tower case
Nocturna dual fans
1 TB HD
Is the PSU from 2013 too? If so you may want to check the functionality of the PSU. The Aurum is a mediocre to good unit, and could well be worn, as PSUs deteriorate over time. I know the Aurums had poorer 3.3V rail regulation, but that shouldn't really cause damage to a GPU.
Have you got a GPU you can borrow from someone else?
Overall I'd put the bets on the GPU, but there's no way to really test without trying another one, the age of the PSU could be indicator. So borrowing a good quality PSU would help test that.